The present invention relates to a joint device for driving the moving sections of a robot apparatus by way of joints and to a walk mechanism having drive means for driving the legs of a robot apparatus. The invention also relates to a drive apparatus having drive means for driving the arms of a robot apparatus, a walking robot apparatus comprising a plurality of legs to be driven by drive means, and a drive force transmitting apparatus for transmitting a drive force from drive means.
Robots shaped like a man and having two legs each and robots shaped like animals and having four legs each have been developed in recent years. Of these walking robots, some are used as industrial robots and the others are used as amusement robots. The industrial walking robots can work in dangerous places to which man cannot walk into. The amusement walking robots can behave like living pets.
The legs of a walking robot are driven by, for example, DC motors. The driving forces are transmitted to the legs via a plurality of gears. The so-called gearbox that contains the DC motors and the gears can drive the legs. The gears are made large and their material is made strong, thereby increasing the strength of the gears. The gears are thereby prevented from being broken due to external shocks they receive.
Any robot that moves while standing is in danger of falling from a high level. The shock the robot receives when it falls onto a lower level may break the gears provided in it.
In the case of a small robot whose leg joints can be easily moved with external forces, an external force may break the drive mechanism provided in the robot. For example, when the joints are forcibly moved with an external force, this force may be transmitted to the drive mechanism, breaking the same. The gearbox incorporated in the robot may contain a shock-absorbing device. If the gearbox incorporates a shock absorber, it will become larger. Any gearbox for driving the joints of a robot should be small and light. If the shock absorber is provided in a gear, the gear will become larger, ultimately increasing the size of the gearbox. Even if the shock absorber is provided outside a gear, the gearbox will become larger.
If the output gear of the gearbox fails to rotate, the motor will stop. In this case, the electric current keeps flowing to one pole only, inevitably generating heat. The heat, thus generated, may damage the drive mechanism.
The problem mentioned above can arise not only at the joints of a robot, but also at any moving section of a robot that is driven by a motor.
The present invention has been made in consideration of the foregoing. An object of the invention is to provide a joint device, a walk mechanism and an arm mechanism, each for use in a robot apparatus and capable of preventing drive means and gears from breaking even if an external force acts on the moving section to which a drive force is transmitted from the drive means such as a motor. Another object of the invention is to provide a walking robot and a drive force transmitting apparatus, each capable of preventing drive means and gears from breaking in such an event.
More specifically, a joint device for use in a robot apparatus, according to this invention, has a first component and a second component that are rotatable around an axle. The device comprises: drive means for transmitting a force through a column of gears; and a slip gear arranged in the column of gears and designed to slip in the direction opposite to the direction the slip gear is rotated with a force transmitted between the drive means and the first or second component, when the force becomes equal to or greater than a predetermined value.
In the joint device having this structure, for use in robot apparatuses, the slip gear slips in the direction opposite to the direction the slip gear is rotated with a force transmitted between the drive means and the first or second component, when the force becomes equal to or greater than a predetermined value.
A walking device for use in a robot apparatus, according to the present invention has leg sections, each designed to be driven by a drive force transmitted from drive means through a column of gears. The walking device comprises: a slip gear arranged in the column of gears and designed to slip in the direction opposite to the direction the slip gear is rotated with a force transmitted between the drive means and one leg section, when the force becomes equal to or greater than a predetermined value.
In the walking device of this structure, the slip gear slips in the direction opposite to the direction the slip gear is rotated with a force transmitted between the drive means and one leg section, when it receives a force that is equal to or greater than a predetermined value. When the clip gear slips so, the transmission of the force between the drive means and the leg section is interrupted.
An arm device for use in a robot apparatus, according to the invention, has arm sections, each designed to be driven by a drive force transmitted from drive means through a column of gears. The arm device comprises: a slip gear arranged in the column of gears and designed to slip in the direction opposite to the direction the slip gear is rotated with a force transmitted between the drive means and one arm section, when the force becomes equal to or greater than a predetermined value.
In the arm device having this structure, the slip gear slips in the direction opposite to the direction the slip gear is rotated with a force transmitted between the drive means and one arm section, when the slip gear receives a force that is equal to or greater than a predetermined value. When the clip gear slips in this manner, the transmission of the force between the drive means and the arm section is interrupted.
A walking robot apparatus according to this invention has a plurality of leg sections, each designed to be driven by a drive force transmitted from drive means through a column of gears. The walking robot apparatus comprises: a slip gear arranged in the column of gears and designed to slip in the direction opposite to the direction the slip gear is rotated with a force transmitted between the drive means and one leg section, when the force becomes equal to or greater than a predetermined value.
In the walking robot apparatus having this structure, the slip gear slips in the direction opposite to the direction the slip gear is rotated with a force transmitted between the drive means and one leg section, when the slip gear receives a force that is equal to or greater than a predetermined value. When the clip gear slips in this way, the transmission of the force between the drive means and the leg section is interrupted.
A drive-force transmitting device according to the present invention comprises a slip gear which slips in the direction opposite to the direction the slip gear is rotated with a force transmitted between the drive means and a component driven by the drive means, when the force becomes equal to or greater than a predetermined value. The slip gear is arranged at a position where the slip gear does not directly mesh with an input-end gear that receives a drive force from the drive means or with an output-end gear that transmits the drive force to the component.
In the drive-force transmitting device thus constructed, the slip gear slips in the direction opposite to the direction the slip gear is rotated with the force when the force becomes equal to or greater than a predetermined value. When the slip gear slips so, the transmission of the force between the drive means and the leg section is interrupted.